He________methathedecidedtoleaveonMonday.
I know it isn ’t important but I can ’t help ________ about it.
Hefellasleepimmediatelylastnight;hemust________(be)verytired.
To succeed in a scientific research project ________.
Matteristhename________(give)toeverythingwhichhasweightandoccupiesspace.
Some molecules are large enough ________ (see) under the electronic microscope.